Amish:
Concerning the current generation of consoles in terms of online gaming, IMHO - XBox's online service is unrivalled. The $200 for an XBox would go far into upgrading a PC - last time I checked the prices of AGP video cards, you can snag a low-end GeForce4 for around that price - not to mention some of ATI's mid to high-end cards as well. Easier said than done, however - one of those video cards will provide minimal benefit on, say - a system with a Pentium II or G3 CPU. PC's will outgun any console - that much is certain. Problem is, the upgrade game is expensive - and for those not willing to shell out massive $$$ for the gaming performance - consoles fill the gap extremely well.
XBox's service is broadband-only, and ideally the internet hookup will be easier than on a Windows machine. Also noteable is the fact that all games will be run through Microsoft's servers, using their infamous Passport interface. That's Big Brother for you, but the service should be a little more stable. We'll see how it goes; fortunately for Gates and Co. they really don't have much competition from Sony and Nintendo in the online gaming venue.

Amish:
Why are those titles sitting in the dust? Especially with the Arc Collection, all 5 of them are worth playing through before picking up any new games. Not to knock on the Fallout games (they are great PC RPGs), but both of those titles have had "bargain bin" status for quite some time - and they are popular enough that they won't disappear anytime soon. If you can spare to chuck $20 for those two games right now and think nothing of it - by all means. Seriously though, the titles you have now are more than enough. The Fallout games are classic - and they can wait.